From 3ceaf5c1309ac8d4d68e6f39c13b021bcc1b15f4 Mon Sep 17 00:00:00 2001
From: Andreas Rumpf <rumpf_a@web.de>
Date: Thu, 1 Jul 2021 17:35:04 +0200
Subject: [PATCH] fixes #18030 (#18415)

---
 compiler/seminst.nim   |  2 +-
 tests/arc/tarcmisc.nim | 30 ++++++++++++++++++++++++++++++
 2 files changed, 31 insertions(+), 1 deletion(-)

diff --git a/compiler/seminst.nim b/compiler/seminst.nim
index 68ab2a310a..e1fad236c6 100644
--- a/compiler/seminst.nim
+++ b/compiler/seminst.nim
@@ -146,8 +146,8 @@ proc instantiateBody(c: PContext, n, params: PNode, result, orig: PSym) =
     freshGenSyms(c, b, result, orig, symMap)
     b = semProcBody(c, b)
     result.ast[bodyPos] = hloBody(c, b)
-    trackProc(c, result, result.ast[bodyPos])
     excl(result.flags, sfForward)
+    trackProc(c, result, result.ast[bodyPos])
     dec c.inGenericInst
 
 proc fixupInstantiatedSymbols(c: PContext, s: PSym) =
diff --git a/tests/arc/tarcmisc.nim b/tests/arc/tarcmisc.nim
index a525380854..5d5d8e914e 100644
--- a/tests/arc/tarcmisc.nim
+++ b/tests/arc/tarcmisc.nim
@@ -28,6 +28,8 @@ aaaaa
 hello
 ok
 true
+copying
+123
 closed
 destroying variable: 20
 destroying variable: 10
@@ -433,3 +435,31 @@ proc t17712 =
   echo el != nil
 
 t17712()
+
+# bug #18030
+
+type
+  Foo = object
+    n: int
+
+proc `=copy`(dst: var Foo, src: Foo) =
+  echo "copying"
+  dst.n = src.n
+
+proc `=sink`(dst: var Foo, src: Foo) =
+  echo "sinking"
+  dst.n = src.n
+
+var a: Foo
+
+proc putValue[T](n: T)
+
+proc useForward =
+  putValue(123)
+
+proc putValue[T](n: T) =
+  var b = Foo(n:n)
+  a = b
+  echo b.n
+
+useForward()